Table 6.5-3. Expected patterns of blood test results during fasting and after mixed meal testing (if plasma glucose <3.0 mmol/L or 55 mg/dL) in normal and pathologic hypoglycemia states

Clinical state

Signs/symptoms

Insulina

C-peptidea

Proinsulina

Beta-HBa

Glucose response to glucagona

OHA

Autoantibodies

Normal

 –

Excess exogenous insulin

Excess sulfonylurea/meglitinide

Insulinoma, NIPHS, PGBH

Insulin autoimmune syndrome

 √ (to insulin)

Insulin receptor autoimmune syndrome

 √ (to insulin receptor)

IGF-2-secreting tumorb

a The symbols represent expected blood test results relative to the normal value or threshold as follows:

– Insulin: 21 pmol/L or 3 microIU/mL.

– C-peptide: 200 pmol/L or 0.6 ng/mL.

– Proinsulin: 5 pmol/L.

– Beta-HB: 2.7 mmol/L.

– Glucose response to glucagon: 1.4 mmol/L or 25 mg/dL.

b Additionally expect increased pro-IGF-2, free IGF-2, and IGF-2/IGF-1 ratio.

Adapted from Journal of Clinical Endocrinology & Metabolism, March 2009, 94(3): 709-728.

–, absent; √, present; beta-HB, beta-hydroxybutyrate; IGF, insulin-like growth factor; NIPHS, noninsulinoma pancreatogenous hypoglycemia syndrome; OHA, oral hypoglycemic agent; PGHB, post–gastric bypass hypoglycemia.